Influence of Ballast Fouling on Reinforced Ballasted Railway Track—A Numerical Investigation

Ballast fouling is a significant problem in railway track infrastructure, as it can lead to reduced track performance, increased maintenance costs, and even derailments. Fouling occurs when fines such as silt and clay infiltrate the ballast layer, which can reduce the ballast's drainage capacity and lead to water accumulation. Geosynthetics have been increasingly used as a solution to ballast fouling, as they can provide reinforcement and confinement to the ballast layer, which helps to prevent the infiltration of fines and the degradation of the ballast. However, the numerical studies related to reinforced ballasted railway tracks are limited. Hence, in the present study, an attempt has been made to investigate the effectiveness of geosynthetics in drainage capacity in the occurrence of ballast fouling through numerical simulation. A finite element seepage analysis was conducted using SEEP/W to assess the effect of ballast fouling on the drainage capacity of reinforced ballasted railway tracks. A parametric study is carried out, including the impact of different levels of fouling with varying depths of placing geogrids/geotextile in improving the drainage capacity of the ballast. It finds that closer placement of geosynthetic layers to the bottom of the track enhances drainage, but increased ballast contamination reduces overall drainage due to decreased strength from the geosynthetics. The study also showed that reinforcement techniques could effectively improve the drainage capacity of the ballast as it delays the ballast fouling.